The present invention relates to a warning device and more particularly relates to an electrical switch actuated by vibration or movement to warn of an intrusion or an impending earthquake.
Earthquakes, which are due to release of internal energy in the earth's core causing a shift of the magma relative to the core, are generally preceded by relatively mild tremors or vibrations termed "foreshock". The principal earthquake usually follows the initial warning tremors by a short period. A warning at the time the first vibrations occur would give persons time to take some precaution to avoid injury and destruction of property. For example, at the time a warning occurs, individuals can seek safe refuge in interior hallways away from exterior windows where glass breakage can cause injury. Adequate advance warning would also allow people to evacuate high-rise buildings. A warning would be extremely important when a quake occurs at night and people are normally asleep.